The Eskimo-Aleut and Ainu languages were historically spoken in the same region (near the Kamchatka Peninsula), and they share some features that are common in Paleo-Siberian languages, including incorporation.
I have also noticed that the native name of the Greenlandic Inuit language (Inuktitut) is similar to the name of the Ainu language (Aynu=itak). In both of these languages, these words means "human language," although I do not know whether this is a coincidence.
Have there been any comparative studies of the Eskimo-Aleut and Ainu languages to identify possible cognates between them?